1. Field of Invention
The present invention relates to a constitution of an ink-jet head for forming an image by ejecting a small liquid drop of ink to a printing face.
2. Description of Related Art
There is a general constitution of an ink-jet head which has been known in the related art and in which a plurality of pressure chambers are formed, a nozzle is opened in correspondence with each of the pressure chambers and each nozzle is connected to one end of a corresponding one of the pressure chambers.
According to the constitution, ink from an ink supply source (for example, ink tank) is temporarily supplied to a common ink chamber and thereafter distributed from the common ink chamber to the plurality of pressure chambers. Further, by selectively applying pressure to each of the pressure chambers by an actuator, ink is ejected from the nozzle in correspondence with the pressure chamber to thereby form an image on a printing face.
The ink-jet head is generally formed by laminating and adhering a plurality of sheets of thin flat plates made of a metal and the like. The pressure chamber and the common ink chamber are formed by etching the metal plates.
Here, there is also known a constitution in which a restriction flow passage having a constitution of narrowing a sectional area of the flow passage between the common ink chamber and the pressure chamber for controlling an amount of ink supplied to the pressure chamber in ejecting ink to thereby prevent an excessive amount of ink from being ejected.
Further, there is also publicly known a constitution in which a damper is provided at the common ink chamber and when pressure variation generated in the pressure chamber in ejecting ink is propagated to the common ink chamber, the pressure variation is absorbed by the damper to thereby prevent a phenomenon (cross talk) in which the pressure variation reaches the other pressure chambers.
Here, in recent years, by needs of high resolution formation of ink-jet recording, miniaturization and high integration of the ink-jet head structure are progressed. Therefore, it is highly requested to be able to simply fabricate an ink-jet head having the above-described restriction flow passage and damper at inside thereof.
It is an object of the invention to provide an ink-jet head having a restriction flow passage and a damper located at the inside thereof, and capable of simplifying fabricating steps.
In order to achieve the above-described object, according to an aspect of the invention, there is provided an ink-jet head comprising a plurality of nozzles for ejecting an ink, a first flat plate layer comprising at least one sheet of flat plates formed by aligning a plurality of pressure chambers communicating with the nozzles respectively in correspondence therewith, a second flat plate layer comprising at least one sheet of the flat plates forming a common ink chamber having a shape elongated in a direction of aligning the pressure chambers, an ink supply passage connecting the common ink chamber and an ink supply source, a flat plate member in a shape of a thin film made of a resin or a metal disposed between the first flat plate layer and the second flat plate layer, a restriction flow passage having one end communicated to the pressure chamber and the other end communicated to the common ink chamber, and a damper chamber formed by a flat plate layer facing the flat plate member on a side thereof opposed to the common ink chamber.
Thereby, the restriction flow passage for controlling an amount of ink supplied to the pressure chamber and the damper for absorbing pressure variation of the common ink chamber can be fabricated as part of the flat plate member and therefore, fabricating steps can be simplified.